I used to be a banker, but I lost interest.
Why this joke works
Interest Is Part of the Job
Losing interest normally means becoming bored or no longer caring about an activity. In banking, interest is also the money paid for borrowing or earned by saving, so a banker who loses it has both a motivation problem and a professional problem. The joke is compact enough that delivery should stay equally simple. Say the first half as an ordinary fact about a former career, pause briefly after “banker,” and let the everyday meaning arrive before the financial one catches up.
A closer look
A Career Change Explained Too Neatly
The phrase “used to be” signals a personal story about why someone left a profession. Instead of supplying workplace drama, the speaker offers a two-word explanation that fits both mood and industry. “But” makes the loss sound decisive, as though every banking career depends on maintaining enthusiasm and a financial rate at the same time.
Fact behind the joke
Interest Can Be Paid on Deposits
Banks may pay interest on customer deposits, and banks themselves hold reserve balances at the Federal Reserve that can also earn interest. The Federal Reserve uses its interest-on-reserve-balances rate as a monetary-policy tool that influences short-term rates. For a real banker, “losing interest” can therefore describe money, pricing, or enthusiasm.